The cartoons are mostly random bizarre occurrences that focus around Tran. He attempts to deal with the situations as best he can, but things always escalate and he is left screaming in terror.

There are currently seven cartoons, which are available on DVD, along with two other shorts called Beyond Grandpa, and are constantly floating around YouTube.

Here Comes Dr. Tran
The short that started it all, toured with the Spike and Mike’s Festival of Animation, and appeared on G4’sLate Night Peep Show.
This cartoon starts off as if it were a movie trailer complete with rating blip. Tran is just sitting at home in his family hut, eating his breakfast before chores, when a dramatic announcer breaks the silence and proceeds to claim Tran is a doctor and a superstar in the international arena. Tran tries to correct the voice, but his pleas go unheard and the whole thing degenerates into increasing insanity over the next seven minutes.
There is even a scene in which the audience is instructed to put on their 3D glasses. The scene consists of Tran in 3D looking confused for a few seconds, before the amazing spectacle of cinematictechnology is over.

Dr. Tran’s Quiet Log Time
This is the shortest, and IMHO funniest of the cartoons which has Tran sitting on a log, roasting what appears to be a slice of ham on a stick over a camp fire. A rooster walks up to Tran, and whispers in his ear, “I’m gonna kill you”. And as Tran runs away screaming the rooster chases him begging for forgiveness.

Dr. Tran Summer Splash
This cartoon starts off with a redheaded kid, and Leland, a kid with a cough drop for a head, sitting in a inflatable pooldebating whether Tran is really an action star. Tran, who is apparently their classmate, is on the other side of the pool denying all their misremembered claims “he’s got a PDF in kicking your ass!”, and the existence of his toy line and truck decals. But it is difficult for him to explain why they are all sitting in a Dr. Tran Inflatable Pool which has his face plastered across the bottom.
Then the announcer comes on to tell everyone how they can win a Dr. Tran Inflatable Pool, several other bizarre items, and a trip for the whole family to ride the Sub Zero Rape Coaster at Six Figs Faggot Mansion Trill Park!

Dr. Tran’s Peanut Butter Square Hula Quest
This is a commercial mimicking old Milton Bradley advertisements which has two boys who at first are amazed by the product, but as the game is explained further they become more and more reluctant to play.

Mr. Tran and the Toy Cack.
This is the longest of the shorts in which, Tran and Leland have been picked up from daycare by Leland’s grandmother. She has taken them out to get ice-cream, and then proceeds to drive them to the toy store. Along the way she says some odd things;

All the while Tran and Leland are screaming and begging for her to stop.

Dickable Afternoons
This is another mock commercial in the thread of classic Pepperidge Farm adverts. The announcer discusses Old Man Dr. Tran and his homemade dickables (whatever those are), while the screen shows the again perplexed Tran interspliced with pictures of farms.
Sources: Dr. Tran cartoons and http://www.lonesausage.com.